LP580projector ?

I am annoyed at having to pay more for the replacment bulb than I paid for my Projector . So I was wondering if there is a way I can supply a 24 v 250w bulb I have ( projection type ) that will fit into my infocus housing . I beleive that the unit can sense the bulb not working and shuts the projector down , but I have been unable to obtain a circuit to follow the neg line back to see if that was the sensor line that controls shut off command . The unit is a LP 580 and it has a sepperate Ballast circuit within the PSU module I was wondering if removing that and if I was to bridge the relay would do the job . then where the Ballast circuit came from I could build a 24v supply for the cheaper lamp .. Regards Vortash